I had a very creative 2 year old that liked to wander. DS1 also had odd sleep patterns that would leave him awake and happy for hours at a time in the middle of the night. I tried the hook and eye thing. He just grabbed a broom and unlocked it! We ended up putting keyed locks on every interior door and storing the key to open it on the door jam trim above the door, even the closets, to keep him out of stuff! For the exterior doors we did the squealer alarms. Those worked quite well on exterior doors, cabinets, and the refrigerator. It let us have a fire escape without locking everyone in the house and let us know exactly where and when he was roaming.